Re: Polygon data modelling question

With great pleasure I have been following this thread. Very interesting subject indeed.

> In some commercial database, they support R tree, which is presented
> at the beginning of 80s. In fact, in 1999, Roger Weber gived a simple
> but efficient method called "VA-file" showing good performance...
> There is a very long story and tons of research on this ... IMO, the
> basic conclusion is: (1) R tree or other R-tree improvements only work
> well in <= 6 dimensional space; (2) VA-file is a promising method for
> high-dimensional space ...

I would simply like to add another perspective that others may have comments on. There are, of course, more than just two data structures out there to address spatial data. Recently I have stumbled across the UB-Trees which I think are part of Transbase, and then we also have Grid Files and GiST for example.

While I see the limitations of R-Trees clearly now (yes, I've read Guttman's paper as well), I'd be interested if anyone on the list has already made some experience with UB-Trees. When would you prefer them, compared to R-Trees for example?

Any comments would be appreciated.

Andi.

-- 
Andreas Bauer, baueran at in.tum.de, http://home.in.tum.de/baueran/
"When your IQ rises to 28, sell." -- Professor Irwin Corey to a heckler